Clamping device by segmental thread pipe for joint

ABSTRACT

A clamping device for coupling and securing firmly a pipe to be coupled to a joint is constructed in such a way that one end or both ends of a joint member is provided with a clamping portion, and a tapered female thread is formed on the internal surface of the clamping portion along the opening edge, and a thread portion and a nut portion are integrally formed and said clamping member is formed in combination of two pieces as a pair so as to be assembled for use, and a tapered male thread is formed on the external surface of the thread portion so as to be screwed to the tapered female thread formed on the clamping portion of the joint member, and also the thread ridge having an identical pitch with that of the tapered male thread formed on the external surface of the thread portion is formed on the internal surface, and a vertical slit groove is notched on the thread portion, and when the thread portion of the clamping member is caused to be screwed into the clamping portion of the joint member, the pipe to be coupled is gradually and uniformly clamped and secured in spiral stripe so as to be firmly coupled, and an engaging step portion for engaging the tip of the pipe to be coupled is formed on the joint member and the clamping member is inserted to the pipe to be connected and when the clamping member is screwed into the clamping portion of the joint member, the pipe to be coupled is prevented from advancing ahead of a predetermined position in the joint member which is accompanied with the screwing of the clamping member, whereby the clamping member is provided with an assembling mechanism and this assembling mechanism prevents the discrepancy of mutual assembling positions when the two pieces of clamping members are assembled as a pair so as to obtain a complete assembly thereof.

States Patent [191 Kojima [54] CLAMPING DEVICE BY SEGMENTAL THREAD PIPEFOR JOINT [76] Inventor: Noriatsu Kojima, No. 31, S-chome,

Y anagishim a-cho Nakagaw a-ku Nagoya, Japan [22] Filed: Sept. 9, 1971[21] Appl. No.: 179,119

[52] [1.8. CI. ..285/357 [51] Int. Cl ..Fl6l 19/00 [58] Field of Search..285/323, 357, 387, 285/322, 226, 343, 393, 392

[56] References Cited UNITED STATES PATENTS 1,538,395 5/1925 Gane..285/357 X 919,913 4/1909 Miller ..285/357 X 1,822,887 9/1931Hagstedt... ..285/357 X 3,079,187 2/1963 Cantor ..285/323 X 2,761,7029/1956 Noel ..285/323 1,606,188 11/1926 Selah ..285/323 2,457,64812/1948 Donner ..285/323 1,372,876 3/1921 Freund ..285/357 1,586,7256/1926 Westinghouse et a1 ..285/226 X A clamping device for coupling andsecuring firmly a pipe to be coupled to a joint is constructed in suchway that one end or both ends of a joint member is provided with aclamping portion, and a tapered female thread is formed on the internalsurface of the clamping portion along the opening edge, and a threadportion and a nut portion are integrally formed and said clamping memberis formed in combination of two pieces as a pair so as to be assembledfor use, and a tapered male thread is formed on the external surface ofthe thread portion so as to be screwed to the tapered female threadformed on the clamping portion of the joint member, and also the threadridge having an identical pitch with that of the tapered male threadformed on the external surface of the thread portion is formed on theinternal surfacefand a vertical slit groove is notched on the threadportion, and when the thread portion of the clamping member is caused tobe screwed into the clamping portion of the joint member, the pipe to becoupled is gradually and uniformly clamped and secured in spiral stripeso as to be firmly coupled, and an engaging step portion for engagingthe tip of the pipe to be coupled is formed on the joint member and theclamping member is inserted to the pipe to be connected and when theclamping member is screwed into the clamping portion of the jointmember, the pipe to be coupled is prevented from advancing ahead of apredetermined position in the joint member which is accompanied with thescrewing of the clamping member, whereby the clamping member is providedwith an assembling mechanism and this assembling mechanism prevents thediscrepancy of mutual assembling positions when the two pieces ofclamping members are assembled as a pair so as to obtain a completeassembly thereof.

1 Claim, 4 Drawing Figures INVENTOR NORIATSU KOJIMA CLAMPING DEVICE BYSEGMENTAL THREAD PIPE FOR JOINT BACKGROUND OF THE INVENTION 1. Field ofthe Invention The present invention relates to a clamping device bythread pipe for joint and particularly, a nut portion and a threadportion are integrally formed and a tapered male thread is formed on theexternal surface of the thread portion, and also the thread ridge havingan identical pitch with that of the tapered male thread is formed on theinternal surface thereof, and a vertical slit groove is notched wherebya clamping member is formed, and this clamping member is formed by twopieces as one pair and is assembled on a thread pipe of segment type anda tapered groove is formed on the internal wall of the clamping portionformed at one end of the joint member and the clamping member formed bytwo pieces in a pair are assembled on the female thread of the clampingportion, and when the clamping member is screwed into the clampingportion of the joint member, the pipe member coupled to the joint memberis firmly fixed and coupled by means of the vertical slit groove of thethread portion and the thread ridge formed on the internal surface, andfurthermore an engaging mechanism is provided on the joint member so asnot to cause the discrepancy of the positions of the pipe to be coupledwhich may be resulted from the screwing of the clamping member.

2. Description of the Prior Art Heretofore, as clamping fixture forclamping a pipe to be coupled to the joint pipe, various types of splitclamping nuts formed with vertical quardrant slits have been used, butthis type of nuts not only require an increased number of parts as theconventional slit clamping nut needs to be clamped by other nut, butalso the discripancy of the coupling position of the pipe to be coupledtends to occur when the clamping operation fails, and the pipe memberfrequently slips off from the joint pipe, and therefore the clampingeffect cannot be sufficiently expected and in addition, the connectingoperation of the joint pipe and pipe member to be coupled has beendifficult.

SUMMARY OF THE INVENTION It is an object of the present invention is toprovide a clamping member formed with a nut portion and a thread portionintegrally, and conventional slit clamping nut needs to be clamped byother nut but in the present invention, as the clamping member is formedintegrally with a nut portion and thread portion, the clamping iseffected without requiring a separate nut.

It is another object of the present invention is to provide a clampingmember which is formed by a threaded pipe of segmental type with twopieces as a set. The clamping member is used by combining two pieces asa set, and fitting of the clamping member can be easily carried out onthe external surface of the pipe member coupled to the joint member, andtherefore the pipe connecting work at a location where piping work isdifficult due to the narrow location can be easily carried out.

It is a further object of the present invention is that a tapered maleridge is formed on the external surface of the thread portion of theclamping member and a corresponding tapered female thread to the taperedmale thread formed on the external surface of the thread portion isformed on the internal surface of the clamping portion of the jointmember so as to make the clamping member is screwable to the jointmember, and furthermore a vertical slit groove is notched on the threadportion of the clamping member so as to clamp the pipe to be coupledelastically.

It is a still further object of the present invention is that a threadridge having an identical pitch with that of a tapered male threadformed on the thread portion is formed on the internal surface of thethread portion of the clamping member and the thread ridge on theinternal surface is arranged to increase the clamping force graduallyand smoothly as the thread is uniform and spiral form with respect tothe pipe to be coupled and being coincided with the clamping force bythe vertical slit groove and the tapered male thread formed on theexternal surface and therefore slipping off can be prevented.

A more specific object of the present invention is that an engagingmechanism is provided on the joint member and a tip of the pipe to becoupled is abutted against the engaging mechanism and when the clampingmember is screwed into the clamping portion of the joint member, theadvancement of the pipe to be coupled in the thread direction which iscaused by the screwing of the clamping member is prevented, and when theclamping operation is effected, the discrepancy of the position of thepipe to be coupled with respect to the joint is prevented, andtroublesome work of adjusting the clamping operation as experiencedconventionally can be eliminated whereby the work efficiency isremarkably improved.

A particular object of the present invention is to provide a clampingmember provided with an assembling mechanism and the discrepancy of theposition when two pieces of the clamping member is assembled as a setcan be prevented and the assembling work of the clamping member can beeasily carried out.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a partly cut-out explanationdrawing showing the condition where a pipe member is coupled to one endof a joint member and the pipe member is firmly coupled to the jointmember,

FIG. 2 is a perspective view of the clamping member,

FIG. 3 is plan view of the clamping member, and

FIG. 4 is an explanation drawing showing the condition where two piecesof clamping members are assembled so as to be installed on the pipebody.

DETAILED DESCRIPTION OF THE INVENTION Briefly, an apparatus of thepresent invention is formed by assembling two pieces of clamping membersas a set which are indicated by letter C, and the assembled clampingmember is screwed into one end of a joint member I and the connection toa clamping member to the pipe member P is firmly clamped and secured.

The joint member I is provided with a clamping portion 1 by forming acylindrical body which is larger than the joint member I in diameter onone end thereof and a tapered female thread 2 is formed on the internalwall of the clamping portion 1 from the edge of the opening, and anengaging step portion 3 is provided at a location slightly remote fromthe tip of this female thread 2 and the tip of the pipe member P whichis inserted and coupled to the joint member J is engaged with the stepportion so as to prevent the advancement of the pipe member P togetherwith the clamping member C beyond a desired position in the joint memberJ and thus the pipe member P is secured in the joint member.

As shown in FIG. 1, the joint member J is bent in its middle portion anda pipe P is fitted to its other end, but the joint member J may beformed linearly, and also it is preferable to provide clamping portionsat both ends of the joint member J and the pipe member P are fitted tosaid both ends of clamping portions.

The clamping member C is provided with a nut portion 4 and a threadportion 5 integrally, and the nut portion 4 is formed in such a way thatan ordinary nut is cut in half, and the thread portion 5 is formed insemi-cylindrical form.

On the external surface of the thread portion 5, a tapered male thread 6is formed in order that the thread portion 5 is screwed to the taperedfemale thread 2 formed on the clamping portion 1 of the joint member J,and also, a thread ridge 7 having a pitch identical with that of saidtapered male thread 6 is formed on the internal surface of the threadportion 5 in order to engage the external peripheral surface of the pipemember P, and a groove portion 8 of vertical slit is notched on thethread portion 5 in the longitudinal direction of the thread portion asshown in FIG. 3 to provide the elastic function to the thread portion 5.When the pipe member P is connected to thejoint member J, the verticalslit groove portion 8 formed on the thread portion 5 is squeezed by thescrewing of the clamping member C to the clamping portion of the jointmember J, and simultaneously, the thread ridge 7 of the internal surfaceof the thread portion 5 is engaged with the external peripheral surfaceof the pipe member P with a pitch identical with the thread pitch of thethread portion 5, and it is elastically engaged and fixed and coupled bythe squeezing action of the groove portion 8. As shown in FIG. 2,projections 9, 10 are protruded on one edge side of the thread portion 5and the edge of one side of the nut portion 4, and depressed portionsll, 12 which correspond and fit to the projections 9, 10

formed at the edge of the respective opposite sides,

whereby a segmental thread pipe is formed by assembling two pieces ofthe clamping members as a set as illustrated in FIG. 1.

Now, as shown in FIG. 1, the pipe member P fitted with a packing 13 isinserted into the joint member 1 and is abutted against the engagingstep portion 3, and two pieces of the clamping member C as one set areassembled on the external periphery of the pipe member P and theclamping member C is screwed to the tapered female thread 2 of theclamping member so that the packing 13 is compressed and the jointmember J and pipe member P become intimately in contact and coupled andsecured.

Furthermore, when the clamping member C is screwed, the vertical slitgroove portion 8 is clamped and the thread ridge 7 formed on theinternal surface of the thread portion 5 ofthe clamping member C isengaged with the external peripheral surface of the pipe member P so asto be elastically engaged and fixed and coupled.

As compared with the conventional clamping fixture which uses slitclamping nut as lock nut for locking the looseness of the clamping nut,the clamping member C according to the present invention in which thethread portion 5 and nut portion 4 are integrally formed sufficientlyserves the purpose, and this clamping member C saves the number of partsto be required and as the clamping member C is formed so as to beassembled from two pieces into one set on the external periphery of thepipe member P, the piping work in the narrow location can be easilycarried out and also as the tapered male thread 6 formed on the externalsurface in the thread portion 5 of the clamping member C and the threadridge 7 formed on the internal surface thereof are formed spirally withan identical pitch, and the thread ridge 7 formed on the internalsurface of the thread portion 5 is of spiral and uniform by beingcoincided with the clamping force of the tapered male thread 6 formed onthe external surface can smoothly increase the clamping force graduallyon the external periphery of the pipe member P abutted and fitted on theengaging step portion of the joint member J. There are many effects suchas that as the pipe member P is abutted and supported on the engagingstep portion 3, troublesome work of adjusting the coupling position byregulating the clamping operation which is required as the clampingmember C is screwed into the joint member J, and the work efficiency canbe remarkably improved. The clamping member C causes no discrepancy ofposition at the time of assembling with the uses of the projections 9,10 and depressed portions 11, 12 which correspond to each other, andthus the operation becomes simple and easy and also it has a simplestructure with minimum number of parts, the production cost of theclamping member can be set to a low level and yet can be constructed incompact form.

Although the invention is described with reference to a preferredembodiment, it will be appreciated by those skilled in the art thatadditions, deletions, modifications and substitutions and other changesnot specifically described and illustrated in this embodiment may bemade which will fall within the purview of the appended claims.

What is claimed is:

1. A clamping device for the end of a hollow pipe comprising incombination:

a hollow joint member having a cylindrical clamping end portion with anenlarged cross-sectional area, said enlarged area having a firstinternal stepped portion with female-type threads tapering inwardly fromthe outer end of said joint member, said first stepped portion definingan annular spacing between said joint member and said pipe,

said enlarged area having a second internal stepped portion located andarranged more remote from the outer end of said joint member than saidfirst stepped portion, a first radially extending shoulder joining saidfirst and second step portions,

a second radially extending shoulder at the inner end of said secondstep portion and adapted to abut the end of said pipe;

a hollow cylindrical clamping assembly having a nut portion means and athread portion means, said thread portion means being positioned withinsaid annular spacing,

said nut and thread portion means being structurally arranged as twosemi-cylindrical portions provided with longitudinal slits diametricallyopposite one another and together forming the split hollow cylindricalclamping assembly,

said longitudinal slits extending the full length of said thread portionmeans,

a pair of outwardly projecting means being formed on the longitudinalsplit edges of each of said semicylindrical portions, one projectingmeans positioned intermediate said thread portions means,

and the other projecting means positioned at the outer end of said nutportion means,

and corresponding recess means being formed on said thread and nutportion means for respectively receiving said projecting means thereinto secure said semi-cylindrical portion firmly together,

said thread portion means having external male-type threads taperingaway from the outer end of said clamping assembly and being operativelyengaging said female-type threads of said first stepped portion,

said thread portion means having internal threads of the same pitch assaid external male-type threads of said thread portion means,

said internal threads of said thread portion means being adapted toengage said pipe; and

an annular packing member positioned within said annular spacingadjacent the inner end of said thread portion means of said clampingassembly and engaging said first shoulder, the penetration of saidthread portion means into said annular spacing urging said packingmember into a fluid tight relationship between said joint member and thesurface of the pipe.

1. A clamping device for the end of a hollow pipe comprising incombination: a hollow joint member having a cylindrical clamping endportion with an enlarged cross-sectional area, said enlarged area havinga first internal stepped portion with female-type threads taperinginwardly from the outer end of said joint member, said first steppedportion defining an annular spacing between said joint member and saidpipe, said enlarged area having a second internal stepped portionlocated and arranged more remote from the outer end of said joint memberthan said first stepped portion, a first radially extending shoulderjoining said first and second step portions, a second radially extendingshoulder at the inner end of said second step portion and adapted toabut the end of said pipe; a hollow cylindrical clamping assembly havinga nut portion means and a thread portion means, said thread portionmeans being positioned within said annular spacing, said nut and threadportion means being structurally arranged as two semi-cylindricalportions provided with longitudinal slits diametrically opposite oneanother and together forming the split hollow cylindrical clampingassembly, said longitudinal slits extending the full length of saidthread portion means, a pair of outwardly projecting means being formedon the longitudinal split edges of each of said semi-cylindricalportions, one projecting means positioned intermediate said threadportions means, and the othEr projecting means positioned at the outerend of said nut portion means, and corresponding recess means beingformed on said thread and nut portion means for respectively receivingsaid projecting means therein to secure said semi-cylindrical portionfirmly together, said thread portion means having external male-typethreads tapering away from the outer end of said clamping assembly andbeing operatively engaging said female-type threads of said firststepped portion, said thread portion means having internal threads ofthe same pitch as said external male-type threads of said thread portionmeans, said internal threads of said thread portion means being adaptedto engage said pipe; and an annular packing member positioned withinsaid annular spacing adjacent the inner end of said thread portion meansof said clamping assembly and engaging said first shoulder, thepenetration of said thread portion means into said annular spacingurging said packing member into a fluid tight relationship between saidjoint member and the surface of the pipe.